Place units in the hippocampus of the freely moving rat

  title={Place units in the hippocampus of the freely moving rat},
  author={John O’Keefe},
  journal={Experimental Neurology},
  • J. O’Keefe
  • Published 31 December 1976
  • Medicine, Psychology
  • Experimental Neurology
Abstract Single units were recorded from the CA1 field of the hippocampus in the freely-moving rat. They were classified as place units, displace units or others. Place units were defined as those for which the rat's position on the maze was a necessary condition for maximal unit firing. Some of these place units (misplace units) fired maximally when the animal sniffed in a place, either because it found something new there or failed to find something which was usually there. Displace units… Expand
Hippocampal place units in the freely moving rat: Why they fire where they fire
All twelve units tested extensively in the controlled enclosure had place fields related to the controlled cues and some units were being excited by one or two cues while others were influenced in a more complex way. Expand
The firing of hippocampal place cells in the dark depends on the rat's recent experience
  • GJ Quirk, R. Muller, JL Kubie
  • Psychology, Medicine
  • The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1990
The results show that place cells can fire differently in identical cue situations and that the best predictor of firing pattern is a combination of current cues and the rat's recent experience. Expand
The contributions of position, direction, and velocity to single unit activity in the hippocampus of freely-moving rats
The pronounced directional selectivity of CS cells, at least in the present environment, suggests that they fire in response to complex, but specific, stimulus features in the extramaze world rather than to absolute place in a non-egocentric space. Expand
Place- and behavior-independent sensory triggered discharges in rat hippocampal CA1 complex spike cells
Single unit recordings of CA1 complex spike cells were made in thirsty rats as they made alternating visits between the center and corners of an enclosed 60×60 cm square arena to test for access of spatial cues to the hippocampus of unrestrained animals. Expand
Place and contingency differential responses of monkey septal neurons during conditional place-object discrimination
The results suggest that septal nuclei are involved in integrating spatial information, conditional place-object relations, and reward/nonreward contingency. Expand
Sensory Determinants of Hippocampal Place Cell Firing Fields
The existence of place cells, the impairments in most spatial tasks caused by hippocampal damage and the clear correlation between the state of the hippocampal EEG and locomotor behavior together strongly suggest that the hippocampus plays a critical role in the processing of spatial information. Expand
Accumulation of Hippocampal Place Fields at the Goal Location in an Annular Watermaze Task
Recordings in rats trained to find a hidden platform at a constant location in a hippocampal-dependent annular watermaze task suggest regions of particular behavioral significance may be over-represented in the hippocampal spatial map, even when these regions are completely unmarked. Expand
Phase relationship between hippocampal place units and the EEG theta rhythm
The phase was highly correlated with spatial location and less well correlated with temporal aspects of behavior, such as the time after place field entry, and the characteristics of the phase shift constrain the models that define the construction of place fields. Expand
Hippocampal Complex Spike Cells do not Change Their Place Fields if the Goal is Moved Within a Cue Controlled Environment
It was concluded that the activity of place cells is related to an animal's location in an environment and that the results accord with cognitive map theory of hippocampal function. Expand
Place cells and silent cells in the hippocampus of freely-behaving rats
  • L. T. Thompson, P. Best
  • Biology, Medicine
  • The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1989
In complex information processing, such as the processing of spatial information by the hippocampus demonstrated here, neural silence may be as important a signal as neural activity. Expand


The hippocampus as a spatial map. Preliminary evidence from unit activity in the freely-moving rat.
Preliminary observations on the behaviour of hippocampusal units in the freely moving rat provide support for this theory of hippocampal function. Expand
Patterns of hippocampal theta rhythm in the freely moving rat.
  • J. Winson
  • Chemistry, Medicine
  • Electroencephalography and clinical neurophysiology
  • 1974
The theta activity that occurs in the presence of eserine and curare was found to have a different amplitude and phase profile from that in the freely moving rat. Expand
Hippocampal electrical activity and voluntary movement in the rat.
  • C. H. Vanderwolf
  • Psychology, Medicine
  • Electroencephalography and clinical neurophysiology
  • 1969
It is suggested that rhythmical slow activity in the hippocampus and diencephalon are the electrical sign of activity in a forebrain mechanism which organizes or initiates higher (voluntary) motor acts. Expand
Studies on single neurons in dorsal hippocampal formation and septum in unrestrained rats. II. Hippocampal slow waves and theta cell firing during bar pressing and other behaviors.
Electrode placement within the hippocampus was critical with regard to how much slow-wave theta could be recorded during voluntary behaviors, whereas theta cells throughout the hippocampus were identical in the form of their firing. Expand
Cognitive maps in rats and men.
  • E. Tolman
  • Psychology, Medicine
  • Psychological review
  • 1948
Most of the rat investigations, which I shall report, were carried out in the Berkeley laboratory, and a few, though a very few, were even carried out by me myself. Expand
Fornix lesions selectively abolish place learning in the rat
Rats with lesions in the fornix, a major afferent/efferent pathway of the hippocampus, failed on a water-finding task when place learning was required but succeeded in the same task when cuelearning was required, indicating that the hippocampus functions as a cognitive mapping system. Expand